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Question #46841
The Question
During the transition of a localized epithelial tumor into a malignant, metastatic carcinoma, the neoplastic cells lose their apical-basal polarity and detach from the basement membrane. According to the principles of cellular organization and cancer biology, which of the following molecular alterations is most directly responsible for this loss of 'contact inhibition' and subsequent metastasis?
Options
- A.
Downregulation of calcium-dependent E-cadherins in adhering junctions
- B.
Hyperactivation of the telomerase enzyme in the nucleoplasm
- C.
Increased assembly of connexons to form intercellular gap junctions
- D.
Strengthening of tight junctions to prevent the leakage of cytoplasmic contents
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Regulatory_Failure
Understand how NOT, EXCEPT, and logical constraints are used to manipulate exam results.
Concepts Behind This Question
Epithelial Junctions Polarity|Metastasis|Tight_Junctions
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often know that cancer involves telomerase activation and uncontrolled division, but fail to link the specific NCERT concepts of 'Adhering junctions' (cementing) and 'Contact inhibition' to the physical mechanism of metastasis.
The trap is confusing the cause of cellular immortality (telomerase) with the structural cause of invasiveness (loss of cadherins/adhering junctions).
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Structural Organisation in Animals - Class 11 |
| Concept | Epithelial Junctions Polarity |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |